Chapter 12: Respiration in Plants Assertion-Reason Questions | biology Class 11 CBSE

Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 1

Logic Check

Assertion (A): Glycolysis is the only process of respiration in anaerobic organisms. Reason (R): Glycolysis occurs in the cytoplasm and does not require oxygen.

Reasoning Options

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Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 2

Logic Check

Assertion (A): Plants do not need specialised respiratory organs. Reason (R): Each plant part takes care of its own gas-exchange needs with very little transport of gases between parts.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 3

Logic Check

Assertion (A): ATP acts as the energy currency of the cell. Reason (R): ATP is directly used to carry out the oxidation of glucose in respiration.

Reasoning Options

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Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 4

Logic Check

Assertion (A): The Krebs' cycle is also called the tricarboxylic acid cycle. Reason (R): The first product of the Krebs' cycle, citric acid, is a tricarboxylic acid with three carboxyl groups.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 5

Logic Check

Assertion (A): Fermentation releases less than 7% of the energy available in glucose. Reason (R): In fermentation, only glycolysis operates and the ETS and Krebs' cycle do not function.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 6

Logic Check

Assertion (A): Oxygen acts as the final hydrogen acceptor in aerobic respiration. Reason (R): Oxygen is consumed in the very first step of aerobic respiration during glycolysis.

Reasoning Options

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Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 7

Logic Check

Assertion (A): The respiratory pathway is described as amphibolic. Reason (R): The respiratory pathway is involved in both breakdown (catabolism) and synthesis (anabolism) of molecules in the cell.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 8

Logic Check

Assertion (A): The RQ of fats is less than 1. Reason (R): Fats have a higher proportion of hydrogen and carbon relative to oxygen compared to carbohydrates, requiring more O2 for complete combustion than CO2 produced.

Reasoning Options

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Assertion-Reason

Hard difficulty • Check the statement and reason

Hard

Question 9

Logic Check

Assertion (A): The 38 ATP calculated during aerobic respiration of glucose is the actual yield in living cells. Reason (R): In living cells, all pathways work simultaneously and intermediates are continuously withdrawn for biosynthesis.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 10

Logic Check

Assertion (A): Oxidative phosphorylation is different from photophosphorylation. Reason (R): In oxidative phosphorylation, the energy of oxidation-reduction reactions is used to generate the proton gradient, whereas in photophosphorylation, light energy is used.

Reasoning Options

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Assertion-Reason

Hard difficulty • Check the statement and reason

Hard

Question 11

Logic Check

Assertion (A): Cytochrome c is embedded within the inner mitochondrial membrane. Reason (R): Cytochrome c acts as a mobile carrier of electrons between Complex III and Complex IV.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 12

Logic Check

Assertion (A): Sucrose is the entry point for glucose into glycolysis in plants. Reason (R): Sucrose is converted to glucose and fructose by the enzyme invertase before entering glycolysis.

Reasoning Options

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Assertion-Reason

Hard difficulty • Check the statement and reason

Hard

Question 13

Logic Check

Assertion (A): FADH2 produces fewer ATP molecules than NADH when oxidised through the ETS. Reason (R): FADH2 donates electrons directly to ubiquinone via Complex II, bypassing Complex I, so fewer protons are pumped.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 14

Logic Check

Assertion (A): Lactic acid fermentation and alcoholic fermentation both result in the reoxidation of NADH to NAD+. Reason (R): Regeneration of NAD+ is essential to allow continued glycolysis under anaerobic conditions.

Reasoning Options

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Assertion-Reason

Hard difficulty • Check the statement and reason

Hard

Question 15

Logic Check

Assertion (A): The Krebs' cycle produces more ATP directly than glycolysis. Reason (R): The Krebs' cycle produces 1 GTP per turn via substrate-level phosphorylation, while glycolysis produces a net of 2 ATP per glucose.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 16

Logic Check

Assertion (A): In plants, living cells in the interior of thick woody stems require lenticels for gas exchange. Reason (R): The interior of thick woody stems consists entirely of dead cells that provide only mechanical support and have no respiratory needs.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 17

Logic Check

Assertion (A): Proteins can serve as respiratory substrates in plants under certain conditions. Reason (R): Proteins are degraded to amino acids, which after deamination can enter the respiratory pathway as pyruvate, acetyl CoA, or Krebs' cycle intermediates.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 18

Logic Check

Assertion (A): Glycolysis is universally present in all living organisms. Reason (R): Glycolysis evolved before oxygen was available on Earth and does not require oxygen.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 19

Logic Check

Assertion (A): The breakdown of glucose during respiration is carried out in one step releasing all energy as heat. Reason (R): Step-wise oxidation of glucose allows energy to be released gradually and coupled to ATP synthesis at specific steps.

Reasoning Options

ByteNotes

Assertion-Reason

Hard difficulty • Check the statement and reason

Hard

Question 20

Logic Check

Assertion (A): The F0 component of ATP synthase contains the catalytic site for ATP synthesis. Reason (R): F0 is an integral membrane protein complex that forms the proton channel through which H+ ions cross the inner mitochondrial membrane.

Reasoning Options

ByteNotes

Chapter sections

Chapter 12: Respiration in Plants | Assertion-Reason

Assertion (A): Glycolysis is the only process of respiration in anaerobic organisms. Reason (R): Glycolysis occurs in the cytoplasm and does not require oxygen.

Assertion (A): Plants do not need specialised respiratory organs. Reason (R): Each plant part takes care of its own gas-exchange needs with very little transport of gases between parts.

Assertion (A): ATP acts as the energy currency of the cell. Reason (R): ATP is directly used to carry out the oxidation of glucose in respiration.

Assertion (A): The Krebs' cycle is also called the tricarboxylic acid cycle. Reason (R): The first product of the Krebs' cycle, citric acid, is a tricarboxylic acid with three carboxyl groups.

Assertion (A): Fermentation releases less than 7% of the energy available in glucose. Reason (R): In fermentation, only glycolysis operates and the ETS and Krebs' cycle do not function.

Assertion (A): Oxygen acts as the final hydrogen acceptor in aerobic respiration. Reason (R): Oxygen is consumed in the very first step of aerobic respiration during glycolysis.

Assertion (A): The respiratory pathway is described as amphibolic. Reason (R): The respiratory pathway is involved in both breakdown (catabolism) and synthesis (anabolism) of molecules in the cell.

Assertion (A): The RQ of fats is less than 1. Reason (R): Fats have a higher proportion of hydrogen and carbon relative to oxygen compared to carbohydrates, requiring more O2 for complete combustion than CO2 produced.

Assertion (A): The 38 ATP calculated during aerobic respiration of glucose is the actual yield in living cells. Reason (R): In living cells, all pathways work simultaneously and intermediates are continuously withdrawn for biosynthesis.

Assertion (A): Oxidative phosphorylation is different from photophosphorylation. Reason (R): In oxidative phosphorylation, the energy of oxidation-reduction reactions is used to generate the proton gradient, whereas in photophosphorylation, light energy is used.

Assertion (A): Cytochrome c is embedded within the inner mitochondrial membrane. Reason (R): Cytochrome c acts as a mobile carrier of electrons between Complex III and Complex IV.

Assertion (A): Sucrose is the entry point for glucose into glycolysis in plants. Reason (R): Sucrose is converted to glucose and fructose by the enzyme invertase before entering glycolysis.

Assertion (A): FADH2 produces fewer ATP molecules than NADH when oxidised through the ETS. Reason (R): FADH2 donates electrons directly to ubiquinone via Complex II, bypassing Complex I, so fewer protons are pumped.

Assertion (A): Lactic acid fermentation and alcoholic fermentation both result in the reoxidation of NADH to NAD+. Reason (R): Regeneration of NAD+ is essential to allow continued glycolysis under anaerobic conditions.

Assertion (A): The Krebs' cycle produces more ATP directly than glycolysis. Reason (R): The Krebs' cycle produces 1 GTP per turn via substrate-level phosphorylation, while glycolysis produces a net of 2 ATP per glucose.

Assertion (A): In plants, living cells in the interior of thick woody stems require lenticels for gas exchange. Reason (R): The interior of thick woody stems consists entirely of dead cells that provide only mechanical support and have no respiratory needs.

Assertion (A): Proteins can serve as respiratory substrates in plants under certain conditions. Reason (R): Proteins are degraded to amino acids, which after deamination can enter the respiratory pathway as pyruvate, acetyl CoA, or Krebs' cycle intermediates.

Assertion (A): Glycolysis is universally present in all living organisms. Reason (R): Glycolysis evolved before oxygen was available on Earth and does not require oxygen.

Assertion (A): The breakdown of glucose during respiration is carried out in one step releasing all energy as heat. Reason (R): Step-wise oxidation of glucose allows energy to be released gradually and coupled to ATP synthesis at specific steps.

Assertion (A): The F0 component of ATP synthase contains the catalytic site for ATP synthesis. Reason (R): F0 is an integral membrane protein complex that forms the proton channel through which H+ ions cross the inner mitochondrial membrane.

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